History

Jungle Armor was previously known as Cobalt Armor, but Cobalt was replaced with Jungle Armor to fit the Jungle setting. i.e. anyone who had any piece of the Cobalt Armor had it replaced with the Jungle Armor of the same type.

This set used to be a rare drop from various Jungle mobs, but as of Patch 1.0.5, it is no longer a drop, and must be crafted.

According to the picture that was posted in Dev Blog, the set bonus would be getting "16% reduced mana usage".

In 1.0.6, the recipes for each piece were changed to need only one gem of each type. (one Diamond, one Topaz, etc.)

As of 1.2, gems are no longer required to craft Jungle Armor.

Trivia

In old versions of Terraria, jungle armor needed gems to craft although the gems never appeared in the sprite or on the player whilst being worn.